Mushroom mousse(-ish) that takes well moderate heat

I am trying to come up with some kind of mousse, based on mushrooms, to be put on top of slices of potatoes just out of the deep-fryer. One of the main difficulties I'm facing is that my attempts tend to "melt" when exposed to the heat of the potato slice. I had a few first attempts, with

a béchamel-like cream, cooked with a roux with a rather firm texture; it turns out a bit too thick and is not as pleasant as a lighter mousse;
a whipped-cream base: cook the mushrooms in cream, cool it down, blend it and whip it. The texture is not optimal, and it "melts" quite quickly when exposed to heat;
I thought of some method based on starch, but didn't try it yet;
I also thought of adding a bit of gelatin or agar-agar, but I'm not confident in the proportions to use here — I certainly don't want a jelly here. It should also remain vegetarian, so agar-agar is preferred.

What options seems most promising to you? Are there any other possibilities or tricks that I could use?

heat mousse

Best Answer

There are dozens of possibilities to make something that has a creamy texture and tastes of mushrooms. It is up to your personal taste to try several ones and decide which you like the most.

Your best bet is probably a molecular gastronomy recipe. Traditional recipes don't include that many savory mousses, and as you found out, the most commonly whippable substance, dairy cream, requires refrigeration. So your best chance to get to something that works is to search recipes for "mushroom foam" and give a preference to molecular gastronomy-related sources. It should be easy to check whether the thickener they use is heat-stable, there are many resources listing the physical properties of different thickeners, and you can usually find the information online. You may need a whipping siphon for most recipes of this kind.

Also, since the texture and mouthfeel of differnet foams can be very different, and some of them may be a bit difficult to get right if you don't have much experience, it is best to get the materials for several recipes and experiment a bit, until you have found something that suits you.

If this is too much hassle for you, you could relax your requirements of getting an actual, foamy mousse. You have already found out that you don't enjoy mushroom pudding, but you might turn out to like different kinds of mushroom dips, for example something based on cream cheese. Or a mixture of quark and mushroom bechamel. Just research different kind of dips, and again, experiment to pick one you like.